Glacier melting rate documented

Bruno Jourdain, a glaciologist with the national observation service GLACIOCLIM, reported that the Saint-Sorlin glacier in the Grandes-Rousses massif in Savoie has melted 5.40 meters in one year, based on measurements of collapsed poles retrieved from the glacier.

Long-term thinning observed

The glacier has lost more than 80 meters in thickness since 1900 and currently remains at a maximum thickness of about 60 meters. Jourdain noted that the glacier has been under scientific monitoring for decades, with markers planted since 1957.

Accelerated melting since 1985

Measurements show that melting has accelerated after 1985, particularly after 2002, with a loss of two meters of water equivalent per year between 2002 and 2022, according to a joint study by researchers from CNRS and specialized institutes in Grenoble, Toulouse, and Aix-Marseille.

Rapid thinning in recent decades

The thinning of Saint-Sorlin is "very rapid in the last two decades," reaching 1.2 meters of ice per year at an altitude of 3,100 meters and 2.2 meters at an altitude of 2,850 meters. Jourdain stated that the glacier is likely to disappear before 2050, an "evolution much faster than the median scenario previously considered."

Significant volume loss in recent years

Between 2022 and 2026, "a fifth of the volume of Alpine glaciers has disappeared," according to Jourdain. He noted that only a few glaciers will survive in the Alps, those "that originate very high in altitude," and that there will be a few dozen residual glaciers by 2100, compared to more than 550 currently.

Heatwave impacts melting

The summer of 2026 was marked by a heatwave with a 0°C isotherm that exceeded 5,000 meters on several occasions, and September remained abnormally warm and dry in the Alps, raising concerns about an acceleration in the melting of the Saint-Sorlin glacier.